XRT84L38IB Exar Corporation, XRT84L38IB Datasheet - Page 352

• Manufacturer Part Number: XRT84L38IB
• Description: Network Controller & Processor ICs 8 Ch T1/E1 Framer
• Manufacturer: Exar Corporation

Specifications of XRT84L38IB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XRT84L38
OCTAL T1/E1/J1 FRAMER
In SF mode, the XRT84L38 supports transmission of Yellow Alarm in two ways. When the Yellow Alarm
Generation Select [1:0] bits of the Alarm Generation Register are set to 01 or 11, the second MSB of all DS0
channels is transmitted as zero. This is Yellow Alarm for DS1 standard.
When the Yellow Alarm Generation Select [1:0] bits of the Alarm Generation Register are set to 10, the
Framing bit of Frame 12 is transmitted as one. This is Yellow Alarm for J1 standard.
In ESF mode, the XRT84L38 transmits Yellow Alarm on the 4Kbit/s data link channel. The Facility Data Link
bits are sent in the pattern of eight ones followed by eight zeros. The number of repetitions of this pattern
depends on the duration of Yellow Alarm Generation Select [1:0] bits of the Alarm Generation Register. When
these select bits are set to 01 or 11, the following scenario will happen:
When these select bits are set to 10, Bit 1 of the Yellow Alarm Generation Select forms a pulse that controls the
duration of Yellow Alarm transmission. The alarm continues until Bit 1 goes LOW.
When these select bits are set to 01, the following scenario will happen:
In N mode, when the Yellow Alarm Generation Select [1:0] bits of the Alarm Generation Register are set to 01,
10 or 11, the second MSB of all DS0 channels is transmitted as zero.
In T1DM mode, when the Yellow Alarm Generation Select [1:0] bits of the Alarm Generation Register are set to
01, 10 or 11, the Yellow Alarm bit (the third LSB of Timeslot 23) is set to zero.The table below shows
configurations of the Yellow Alarm Generation Select [1:0] bits of the Alarm Generation Register (AGR).
1. If Bit 0 of Yellow Alarm Generation Select forms a pulse width shorter or equal to the time required to trans-
2. If Bit 0 of Yellow Alarm Generation Select forms a pulse width longer than the time required to transmit 255
3. A second pulse on Bit 0 of Yellow Alarm Generation Select during an alarm transmission resets the pattern
1. If Bit 0 of Yellow Alarm Generation Select forms a pulse width shorter or equal to the time required to trans-
2. If Bit 0 of Yellow Alarm Generation Select forms a pulse width longer than the time required to transmit 255
3. A second pulse on Bit 0 of Yellow Alarm Generation Select during an alarm transmission resets the pattern
9.6.4.2
9.6.4.3
9.6.4.4
mit 255 patterns on the 4Kbit/s data link, the alarm is transmitted for 255 patterns.
patterns on the 4Kbit/s data link, the alarm continues until Bit 0 goes LOW.
counter. The framer will send another 255 patterns of the Yellow Alarm.
mit 255 patterns on the 4Kbit/s data link, the alarm is transmitted for 255 patterns.
patterns on the 4Kbit/s data link, the alarm continues until Bit 0 goes LOW.
counter. The framer will send another 255 patterns of the Yellow Alarm.
Transmit Yellow Alarm in ESF Mode
Transmit Yellow Alarm in N Mode
Transmit Yellow Alarm in T1DM Mode
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